Improving FWHM and Extraction Efficiency of RGB OLEDs with MQW Structure

In this paper, RGB organic light-emitting diodes are developed using a multiple quantum well (MQW) structure to improve the average percentage between the far-field power and the dipole source power which is known as the Extraction Efficiency (EE), and the full-width half-maximum (FWHM). Then the proposed structure is compared with a conventional OLED structure. Red ph-OLED QW, in which 4-(dicyanomethylene)-2-(t-butyl)-6-methyl-4H-pyran(DCJTB) doped (8-hydroxyquinoline) aluminum (Alq3) as emitting layer (EML) and N, N′-Di(1-naphthyl)-N, N′-diphenyl-(1,1 ′-biphenyl)-4,4′-diamine (NPB) is used as a hole transport layer (HTL) and interlayer [DCJTB doped Alq3/NPB/ DCJTB doped Alq3]n, Green ph-OLED, in which the 4,4′-bis(Ncarbazolyl)-1,1′-biphenyl (CBP) and tris[2-phenylpyridinatoC2, N]iridium(III) [Ir(ppy)3] are used as the emission layer and N, N′-Di(1-naphthyl)-N, N′-diphenyl-(1,1′-biphenyl)-4,4′-diamine (NPB) are used as a hole transport layer (HTL) and interlayer [CBP: Ir(ppy)3/ TCTA/ CBP: Ir(ppy)3]n and Blue ph-OLED (8-hydroxyquinoline) aluminum (Alq3) and N, N0-diphenyl-N, N0-bis(3-methylphenyl)-1,10-biphenyl-4,40-diamine) (TPD) are used as a hole transport layer (HTL) and interlayer [Alq3/TPD/Alq3]n, n is the well number, which can range from 0 to 6. MQW solved the main problem in the RGB OLEDs: the holes mobility and electrons mobility, which are not the same. Consequently, it leads to the loss and reduction of the Extraction Efficiency (EE). Then, there is a comparison between the output EE before and after applying the MQW on the RGB OLED structures, using the Lumerical Finite Difference Time Domain (FDTD) simulation.